The Castle can be visited
Augustusburg Castle

Augustusburg Palace in Brühl, North Rhine-Westphalia, is an example of Baroque and early Rococo architecture in Germany. Together with the nearby Falkenlust Hunting Lodge and the palace park, it has been a UNESCO World Heritage Site since 1984.
History+
As early as the 12th century, the Archbishops of Cologne owned an estate on this site. In 1284, Archbishop Siegfried had a moated castle built as a defense against Cologne, which was completed in 1298 and later reinforced under Archbishop Walram. However, this castle was blown up by French troops in 1689 during the War of the Palatine Succession. On the ruins of this complex, Archbishop Clemens August I of Bavaria began the construction of the current Augustusburg Palace in 1725. The plans came from the Westphalian architect Johann Conrad Schlaun, using the foundations of the previous building, which led to a slight asymmetry of the side wings.
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Location: 50.8283, 6.9078